Rolling mills

ABSTRACT

A cover for a pit comprises two parts which when arranged in side-by-side relation are together of sufficient size and shape to cover the mouth of the pit. One part of the cover is secureable in the mouth of the pit and the second part is supported on inclined surfaces so that the second part can be displaced from the position where it is side-by-side with the first part with their upper surfaces coplanar to a position in which it is beneath the first part. The cover is particularly suitable for covering a pit adjacent a rolling mill. The movable part of the cover may be connected to a sledge in the mill and carrying the rolls so that on withdrawing the rolls the cover is automatically opened.

United States Patent Fereday et al.

[ 1 June 6, 1972 [54] ROLLING MILLS [72] Inventors: Stanley Fereday,Nottingham; William Harry Smelt, Yorkshire, both of England [73]Assignee: Davy and United Engineering Company FOREIGN PATENTS ORAPPLICATIONS Primary ExaminerCharles W. Lanham AssistantExaminer-Michael .l. Keenan Att0mey-Henry C. Westin [57] ABSTRACT Acover for a pit comprises two parts which when arranged in side-by-siderelation are together of sufficient size and shape [52] US. Cl ..72/238,49/22] to cover the mouth of the pit. One part of the cover is securea-[51] Int. Cl.... ..B2lb 31/08 ble in the mouth of the pit and the secondpart is supported on [58] Field of Search ..72/237, 238, 239; 49/33,234, inclined surfaces so that the second part can be displaced from49/235 209 210, 221 360 the position where it is side-by-side with thefirst part with their upper surfaces coplanar to a position in which itis [56] References Cited beneath the first part. The cover isparticularly suitable for covering a pit adjacent a rolling mill. Themovable part of the UNITED STATES PATENTS cover may be connected to asledge in the mill and carrying the rolls so that on withdrawing therolls the cover is automati- 3,45l,244 6/1969 Stover et al ..72/239Cally opened 3,4l7,509 12/1968 Sherron ...49/209 3,090,264 5/ 1963 Stoneet a1. ..72/84 4 Claims, 3 Drawing Figures 4A 2 92) 7b 37 2.9, 22 /Z\ 440 11 JO 1] 9/4 Jl l x 4; U 2 31/ 92 27 w .2;

I? Z ta- 2:; .1 m .r'. 1 s v 5 21 Z .L J5 Z6 '20 Great Britain ..49/22 IPATENTEDJUM 61972 venlo STANLEY FEREDAY AM HARRY SMELT HENRY C WESUN QRN 0 mm N Mm m 5 Q mm mm mm QM an Aw QM Q Ev Q N m K ax i PKVM... NR

D III" II In! 1/ Z M S Attorn y j ROLLING MILLS This invention relatesto a cover for a pit. Although the word pit" is usually understood tomean a hole or a trench in the ground, it is intended that in thisspecification the word pit should be contrued to include a sunken areabeneath, or a hole in, a floor of a building. A particular, but notsole, application of the invention is to a cover for a pit in the floorof a workshop in which metals are rolled, the pit being on the rollchange side of a rolling mill. When the mill rolls are periodicallyremoved from the mill they are withdrawn into the pit, but when the millis in use the pit has to be covered.

In U.S. Pat. No. 3,204,443 a pit at the roll change side of a rollingmill has a two-part cover with the parts arranged sideby-side. When thepit is to be exposed, the part of the cover adjacent the mill is slidhorizontally to a position underneath the other part of the cover. Thisarrangement however suffers from the serious disadvantage that when bothparts are positioned side-by-side the upper surfaces of the two partsare not co-planar and there is a step between the levels of the twoparts. Serious accidents can occur if a mill operator trips on the stepbetween the two parts of the pit cover. This is particularly likely tohappen if a cobble occurs when the mill is in use and it is necessaryfor the mill operators to run away from the vicinity of the mill topositions of safety.

It is an object of the present invention to provide a two-part pit coverwhich can readily be moved to open the pit and which, when the pit iscovered, provides a flat surface without a step between the two parts.

According to the present invention a cover for a pit (as hereinbeforedefined) comprises first and second parts which when arranged inside-by-side relation are together of sufficient size and shape to closethe mouth of the pit, the first part of the cover being fixedlysecurable in the mouth of the pit and the second part being supported onsurfaces which include inclined portions, the surfaces permitting thesecond part of the cover to be displaceable between a first position inwhich the parts are in side-by-side relation with their upper surfacesco-planar and a second position in which the second part is beneath thefirst.

Preferably the surfaces which include inclined portions are provided bytracks positionable in the pit beneath the cover. Wheels or rollers areconveniently provided on the second part of the cover with the wheels orrollers associated with the tracks.

Although the second part of the pit cover could be moved manuallybetween the first and second positions, it is preferable for the part ofthe cover to be moved by means of a fluid operated piston and cylinderdevice coupled thereto and positionable in the pit beneath the cover.

In order that the invention may be more readily understood, it will nowbe described, by way of example only with reference to the drawingsfiled with the provisional specification, in which:

FIG. 1 is a sectional side elevation of a cover associated with a pit onthe floor at the roll-change side of a rolling mill,

FIG. 2 is a section on the line II-II of FIG. 1,

FIG. 3 is an enlarged view in section of a portion of the coverillustrated in FIG. 1.

In FIG. 1, a rolling mill stand is indicated by reference numeral 12.The stand comprises a pair of identical spaced-apart housings, one ofwhich is shown at 13, and each housing defines a window 14. The millrolls (not shown) are supported at their ends in bearing chockassemblies which are positioned in the housing windows. During rollchanging the chocks are supported on a sledge which is positioned in thebottom of the housings and extends between the windows.

An elongate pit is provided in the mill foundations 21, on the rollchange side. The pit 20 extends normal to the pass-line of the mill. Thepit 20 is covered at mill floor level, represented at 22 in the drawing,by a cover having a first fixed floor plate 23 and a second movablefloor plate 24. The fixed plate 23 is supported at its edges on thefoundations 21 in the mouth of the pit in a position remote from themill stand 12.

In the bottom of the pit 20 a sliding bed 25 is provided which extendsalong approximately half the length of the pit from the roll stand endand at a height level with the bottom of the housing window 14. Adouble-acting fluid operated piston and cylinder unit 26 is supported inthe pit 20 below the fixed plate 23. A piston rod 27 of the unit 26 iscoupled by way of a coupling block 28 to the sledge 15. By operating theunit 26 the sledge 15 is movable relative to the mill stand 12 along thesliding bed 25.

Two pairs of spaced-apart flanged wheels 30, 31 are mounted on bracketsattached to the underside of the movable floor plate 24. Each pair ofwheels 30, 31 is supported on a respective pair of tracks 32, 33. Theends of the rails 32, 33 nearest the mill stand 12 are inclined upwardsto form ramps 34, 35 which terminate in flat tops. The height of theramps 34, 35 is such that when the wheels 30, 31 are on the flat topsthereof the upper surface of the movable floor plate 24 is level withthat of the fixed floor plate 23. The angle of inclination of the ramps34, 35 is such that when the movable plate 24 is moved to the right inFIG 1, it moves under the fixed floor plate 23 to a position shown inchain lines. To facilitate this operation a portion 36 of the fixedfloor plate 23 which is adjacent the plate 24 is hinged at 37. A roller38 is provided on the underside of the hinged portion 36. When themovable plate 24 is moved to the right in FIG. 1, the roller 38 engagesa cam surface 39 provided on the plate 24 which causes the portion 36 toswing upwards clear of the plate 24.

The movable floor plate 24 follows simultaneously the movements of thesledge 15 by means of a link 40 pivotally attached to brackets 41, 42secured to the block 28 and the plate 24 respectively.

FIG. 2 shows the cross-sectional layout of the various parts of thedescribed apparatus on the line II-II of FIG. 1. The central portion ofthe bottom of the pit 20 is occupied by the sliding bed 25 so that thesledge 15 can be withdrawn from the window 14 without fouling anyfittings. The rails 32, 33 and the ramps 34, 35 are supported along thebottom edges of the pit 20. It is to be noted that the pair of rails 32and their associated ramps 34 are located inboard of the other pair ofrails 33 and the ramps 35. This is because the wheels 30 have to rollpass the ramps 35 when the movable plate 24 is displaced to the right inFIG. 1 and if the wheels of each pair 30, 31 were spaced equally apartthen this would not be possible.

When changing the back-up rolls in the mill stand 12, the work rolls(not shown) are first removed and then either the lower back-up roll orthe upper back-up roll (not shown) supported on the chocks 16 of thelower back-up roll so as to form a unit, is removed from the mill stand12 by actuating the piston and cylinder unit 26. Simultaneously themovable floor plate 24 is pulled down the ramps 34, 35 and along therails 32, 33 until the plate 24 is in the position shown in the chainlines in FIG. 1. By this time the sledge 15 with its load is positionedin the pit 20 below the opening left by the plate 24. A crane thenremoves the old roll or rolls with their chocks from the sledge andreplaces them on the sledge with a new roll or rolls. The sledge 15 andthe movable plate 24 are returned to the position shown in full lines inFIG. 1.

If desired the pairs of wheels 30, 31 may be replaced by roller orskids.

In accordance with the provisions of the patent statutes, we haveexplained the principles and operation of our invention and haveillustrated and described what we consider to represent the bestembodiment thereof.

We claim:

1. A cover for a pit, the cover comprising first and second parts whichwhen arranged in side-by-side relation are together of sufiicient sizeand shape to close the mouth of the pit, the first part of the coverbeing fixedly securable in the mouth of the pit and the edge of thefirst part which is adjacent the second part when the two parts are inside-by-side relation being defined by a member separate from theremainder of the first part and hinged thereto, said second part havingwheels provided on the underside at the opposite ends thereof which areadjacent and away from the first part respectively when the two partsare in side-by-side relation, said wheels at one end of the second partbeing associated with first track means which include inclined portionsand which are positionable in the pit beneath the cover and the wheelsat the other end of the second part being associated with further trackmeans which includeinclined portions and which are positionable in thepit laterally with respect to said first track means, said inclinedportions of the track means permitting the second part of the cover tobe displaceable between a first position in which the parts are inside-by-side relation with their upper surfaces coplanar and a secondposition in which the second part is beneath the first part, cooperatingmeans carried by said hinged member of the first part of the cover andsaid second part of the cover which cause said hinged member to pivotaway from the second part when the second part is displaced from thefirst position to the second position and a fluid operatedpiston-cylinder device operatively coupled to said second part andlocatable in said pit and which serves to displace said second partbetween the first and second positions.

2. A pit cover as claimed in claim 1 in which said-CO-Operating meanscomprise a roller on said hinged part and a cam surface on the secondpart.

3. A pit cover as claimed in claim 1 in which the cover is associatedwith a pit at the roll change side of a rolling mill, the cover ispositionable at floor level with the second part of the cover adjacentthe rolling mill. 7

4. Apit cover as claimed in claim 1 in which a sledge is positioned inthe mill to support the rolls during roll changing and the sledge iscoupled to said piston and cylinder device, whereby displacement of thesecond part of the cover to the second position causes the sledge to bedisplaced into the pit.

1. A cover for a pit, the cover comprising first and second parts whichwhen arranged in side-by-side relation are together of sufficient sizeand shape to close the mouth of the pit, the first part of the coverbeing fixedly securable in the mouth of the pit and the edge of thefirst part which is adjacent the second part when the two parts are inside-by-side relation being defined by a member separate from theremainder of the first part and hinged thereto, said second part havingwheels provided on the underside at the opposite ends thereof which areadjacent and away from the first part respectively when the two partsare in side-by-side relation, said wheels at one end of the second partbeing associated with first track means which include inclined portionsand which are positionable in the pit beneath the cover and the wheelsat the other end of the second part being associated with further trackmeans which include inclined portions and which are positionable in thepit laterally with respect to said first track means, said inclinedportions of the track means permitting the second part of the cover tobe displaceable between a first position in which the parts are inside-by-side relation with their upper surfaces coplanar and a secondposition in which the second part is beneath the first part, cooperatingmeans carried by said hinged member of the first part of the cover andsaid second part of the cover which cause said hinged member to pivotaway from the second part when the second part is displaced from thefirst position to the second position and a fluid operatedpiston-cylinder device operatively coupled to said second part andlocatable in said pit and which serves to displace said second partbetween the first and second positions.
 2. A pit cover as claimed inclaim 1 in which said co-operating means comprise a roller on saidhinged part and a cam surface on the second part.
 3. A pit cover asclaimed in claim 1 in which the cover is associated with a pit at theroll change side of a rolling mill, the cover is positionable at floorlevel with the second part of the cover adjacent the rolling mill.
 4. Apit cover as claimed in claim 1 in which a sledge is positioned in themill to support the rolls during roll changing and the sledge is coupledto said piston and cylinder device, whereby displacement of the secondpart of the cover to the second position causes the sledge to bedisplaced into the pit.